[PATCH 1/3] Reload fd ioctl handler on each call to ioctl

[Carl Fredrik Hammar]

* hurd/hurdioctl.c (_hurd_dummy_ioctl_handler): New function.
* hurd/hurd/ioctl.h (_hurd_dummy_ioctl_handler): Likewise.
* hurd/fd-ioctl-call.c: New file.
* hurd/hurd/fd.h: Update copyright years.
(_hurd_fd_call_ioctl_handler): New function declaration.
* hurd/Makefile: Update copyright years.
(user-interfaces): Add `ioctl_handler'.
(dtable): Add `fd-ioctl-call'.
* sysdeps/mach/hurd/ioctl.c: Update copyright years.
(__ioctl): Call fd ioctl handler.
---
 hurd/Makefile             |    7 ++-
 hurd/fd-ioctl-call.c      |   90 +++++++++++++++++++++++++++++++++++++++++++++
 hurd/hurd/fd.h            |    6 ++-
 hurd/hurd/ioctl.h         |    5 ++
 hurd/hurdioctl.c          |    9 ++++-
 sysdeps/mach/hurd/ioctl.c |   12 +++++-
 6 files changed, 123 insertions(+), 6 deletions(-)
 create mode 100644 hurd/fd-ioctl-call.c

diff --git a/hurd/Makefile b/hurd/Makefile
index ff6b7cb..4ad5128 100644
--- a/hurd/Makefile
+++ b/hurd/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 1991,92,93,94,95,96,97,98,99,2001,2002,2004,2006
+# Copyright (C) 1991,92,93,94,95,96,97,98,99,2001,2002,2004,2006,2009
 #      Free Software Foundation, Inc.
 # This file is part of the GNU C Library.
 
@@ -40,7 +40,7 @@ user-interfaces               := $(addprefix hurd/,\
                                       msg msg_reply msg_request \
                                       exec exec_startup crash interrupt \
                                       fs fsys io term tioctl socket ifsock \
-                                      login password pfinet \
+                                      login password pfinet ioctl_handler \
                                       )
 server-interfaces      := hurd/msg faultexc
 
@@ -67,7 +67,8 @@ sig   = hurdsig hurdfault siginfo hurd-raise preempt-sig \
          thread-self thread-cancel intr-msg catch-signal
 dtable = dtable port2fd new-fd alloc-fd intern-fd \
          getdport openport \
-         fd-close fd-read fd-write hurdioctl ctty-input ctty-output
+         fd-close fd-read fd-write hurdioctl ctty-input ctty-output \
+         fd-ioctl-call
 inlines = $(inline-headers:%.h=%-inlines)
 distribute = hurdstartup.h hurdfault.h hurdhost.h sysvshm.h \
             faultexc.defs intr-rpc.defs intr-rpc.h intr-msg.h Notes
diff --git a/hurd/fd-ioctl-call.c b/hurd/fd-ioctl-call.c
new file mode 100644
index 0000000..c5a41e8
--- /dev/null
+++ b/hurd/fd-ioctl-call.c
@@ -0,0 +1,90 @@
+/* Call descriptors ioctl handler.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#include <hurd.h>
+#include <hurd/fd.h>
+#include <hurd/ioctl.h>
+#include <hurd/ioctl_handler.h>
+#include <dlfcn.h>
+#include <stdio.h>
+#include <unistd.h>
+
+
+/* Get PORT's ioctl handler module and load it, returning the linker map
+   in MAP as returned by `dlopen'.  */
+
+static error_t
+load_ioctl_handler (io_t port, void **map)
+{
+  io_t handler;
+  error_t err;
+
+  err = __ioctl_handler_get (port, &handler);
+  if (!err)
+    {
+      int fd = _hurd_intern_fd (handler, 0, 1);  /* Consumes HANDLER.  */
+      if (fd == -1)
+       err = errno;
+      else
+       {
+         char *name;
+         err = __asprintf (&name, "/dev/fd/%d", fd);
+         if (err == -1)
+           err = errno;
+         else
+           {
+             *map = __libc_dlopen (name);
+             free (name);
+             err = 0;
+           }
+         __close (fd);
+       }
+    }
+
+  return err;
+}
+
+
+/* Call D's ioctl handler, loading it from the underlying port if
+   necessary.  Arguments are the same as ioctl handlers.  */
+
+int
+_hurd_fd_call_ioctl_handler (int fd, int request, void *arg)
+{
+  ioctl_handler_t ioctl_handler;
+  void *ioctl_handler_map;
+  int result;
+  error_t err;
+
+  /* Avoid spurious "may be used uninitialized" warning.  */
+  ioctl_handler_map = NULL;
+
+  err = HURD_DPORT_USE (fd, load_ioctl_handler (port, &ioctl_handler_map));
+  if (!err && ioctl_handler_map)
+    ioctl_handler = __libc_dlsym (ioctl_handler_map, "hurd_ioctl_handler");
+  if (err || !ioctl_handler_map || !ioctl_handler)
+    ioctl_handler = _hurd_dummy_ioctl_handler;
+
+  result = (*ioctl_handler) (fd, request, arg);
+
+  if (ioctl_handler_map)
+    __libc_dlclose (ioctl_handler_map);
+
+  return result;
+}
diff --git a/hurd/hurd/fd.h b/hurd/hurd/fd.h
index 2a981f4..6ea9ad6 100644
--- a/hurd/hurd/fd.h
+++ b/hurd/hurd/fd.h
@@ -1,6 +1,6 @@
 /* File descriptors.
    Copyright (C) 1993,1994,1995,1996,1997,1998,1999,2000,2001,2002,2006,2007
-       Free Software Foundation, Inc.
+       2009 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -291,5 +291,9 @@ extern file_t __directory_name_split_at (int fd, const char 
*directory_name,
                                         char **name);
 
 
+/* Call D's ioctl handler, loading it from the underlying port if
+   necessary.  Arguments are the same as ioctl handlers.  */
+extern int _hurd_fd_call_ioctl_handler (int fd, int request, void *arg);
+
 
 #endif /* hurd/fd.h */
diff --git a/hurd/hurd/ioctl.h b/hurd/hurd/ioctl.h
index e5ab3dc..f932fa1 100644
--- a/hurd/hurd/ioctl.h
+++ b/hurd/hurd/ioctl.h
@@ -74,4 +74,9 @@ extern int hurd_register_ioctl_handler (int first_request, 
int last_request,
 ioctl_handler_t _hurd_lookup_ioctl_handler (int request);
 
 
+/* A dummy handler that always fails.  */
+
+int _hurd_dummy_ioctl_handler (int fd, int request, void *arg);
+
+
 #endif /* hurd/ioctl.h */
diff --git a/hurd/hurdioctl.c b/hurd/hurdioctl.c
index 13a1a78..0b91ee1 100644
--- a/hurd/hurdioctl.c
+++ b/hurd/hurdioctl.c
@@ -1,5 +1,5 @@
 /* ioctl commands which must be done in the C library.
-   Copyright (C) 1994,95,96,97,99,2001,02 Free Software Foundation, Inc.
+   Copyright (C) 1994,95,96,97,99,2001,02,09 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -50,6 +50,13 @@ _hurd_lookup_ioctl_handler (int request)
   return NULL;
 }
 
+/* A dummy handler that always fails.  */
+int
+_hurd_dummy_ioctl_handler (int fd, int request, void *arg)
+{
+  return __hurd_fail (ENOTTY);
+}
+
 #include <fcntl.h>
 
 /* Find out how many bytes may be read from FD without blocking.  */
diff --git a/sysdeps/mach/hurd/ioctl.c b/sysdeps/mach/hurd/ioctl.c
index 769eb68..736ad8e 100644
--- a/sysdeps/mach/hurd/ioctl.c
+++ b/sysdeps/mach/hurd/ioctl.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992,93,94,95,96,97,99,2000,2002,2005
+/* Copyright (C) 1992,93,94,95,96,97,99,2000,2002,2005,2009
        Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -220,6 +220,16 @@ __ioctl (int fd, unsigned long int request, ...)
     }
 
   {
+    int save = errno;
+    int result = _hurd_fd_call_ioctl_handler (fd, request, arg);
+    if (result != -1 || errno != ENOTTY)
+      return result;
+
+    /* The handler doesn't grok this one.  Try linked handlers.  */
+    errno = save;
+  }
+
+  {
     /* Check for a registered handler for REQUEST.  */
     ioctl_handler_t handler = _hurd_lookup_ioctl_handler (request);
     if (handler)
-- 
1.6.3.3